Routing & Switching: allow for connecting devices

Router: different network

switching: same network

Hub: receives data/sends to everyone

doesn;t care/track the MAC address and doesn't inspect the packet we send


smart hub

only sending packet to the device that need to have it or the devices correspond to those ports

Multi layer switch:

can perform routing and switching layer 2 &3


connect network segment

break up/segment traffic


2 types: Increase signal (amplify) or Signal regeneration = clean

Routing table

In computer networking a routing table, or routing information base (RIB), is a data table stored in a router or a networked computer that lists the routes to particular network destinations, and in some cases, metrics (distances) associated with those routes.

Routing table can be: static or dynamic

Static routing table is what we manually installed everything

Dynamic routing table tries to find the best route to take


Maximum transmission unit: is the width of data we can put through on the single link at once => the maximum of data we can put through the single link at once

II/ Routing:

IGP & EGP protocol

IGP: Intertal gateway protocol

Inside autonomous network

EGP : Exterior gateway protocol

Connecting external network and routers


Broadcast domain:

Broadcast domain is an area of network where an broadcast message can reach.

+All devices that can be reached at layer 2.

+does not pass Routers.

Collision domain: area of the network where 2 devices or more than 1 devices would have talked at the same time. it will create data collision

Collision domain can be:


VLAN: Virtual local area network * broadcast go to same VLAN

Have: +Access ports: devices -> switch +trunk ports: :switch -> switch : allow us to have access on multiple VLANs

V/ Port mirroring:

[from wikipedia]

Port mirroring is used on a network switch to send a copy of network packets seen on one switch port (or an entire VLAN) to a network monitoring connection on another switch port. This is commonly used for network appliances that require monitoring of network traffic such as an intrusion detection system, passive probe or real user monitoring (RUM) technology that is used to support application performance management (APM).

Port mirroring on a Cisco Systems switch is generally referred to as Switched Port Analyzer (SPAN) or Remote Switched Port Analyzer (RSPAN). Other vendors have different names for it, such as Roving Analysis Port (RAP) on 3Com switches.